samplers loopers and midi

I don't know if this has already been discussed but for the longest time
I've been in search for a looping/sampler set-up similar to the new Boss
RC-50 but slightly different. Basically i'd like to take a sampler device
similar to the Roland SP-404 (midi syncable) and trigger samples on it
from
a midi foot pedal, like that Behringer one but smaller. Does anyone know
of
a more compact midi foot pedal that sends midi note on/off signals?
Basically I'd like to designate one pedal to one sample pad on the SP-404
or
similar unit. Sounds like the RC-50 might be the easiest option, anyone
know
when it's coming out in the US?